I have a chemigen D10 and the orp was set to around 650
everything was good but when I test my chlorine its high around the 3 - 4
ive keep dropping the ORP but its not doing to much
its down to 590 and the level of chlorine is 4.5
PH is OK around 7.5
What happening, what am I doing wrong.
Standard sand filter
Pool 64,000 litres